The site of Castelgrande has been fortified since at least the late 1st century BC and until the 13th century it was the only fortification in Bellinzona. During its history the castle has been known as the stronghold (before the 13th century), the Old Castle in the 14–15th centuries, Un Castle after 1506 and Saint Michael's Castle from 1818.
The Castelgrande hill includes a nearly vertical side on the north and a steep southern side, but is nearly flat and 150–200 meters in diameter. The natural shape of the hill has encouraged every man-made fortification to follow the same contours. While the Roman fort is not visible the Roman foundations were used by the High Middle Ages castle which followed. Of the High Middle Ages castle the only visible parts are a few pieces of wall that are still standing. Much of the visible castle dates from 1250–1500 with extensive renovations and some expansion in the last two centuries. Most of the area inside the castle walls is now flat, open space.
Records from the 11th to 15th centuries as well as archeological evidence indicate that the castle grounds were once full of buildings. However most of these were pulled down by the Dukes of Milan to free up interior space. The open space was divided into 3 large baileys which served to provide temporary housing for troops that could be stationed in Bellinzona. Under the Dukes of Milan the outer fortifications were extended and strengthened. The walls were raised, extended and towers were added. The western walls were totally rebuilt and connected to the city walls.
The walls that separate the three baileys all radiate from the 14th century Terre Nera, which is located in the center of the castle. To the east is a complex of buildings which were part of the old keep in the castle. In the center of the keep is the tallest tower of Castelgrande, the Torre Bianca or White Tower, which dates from the 13th century. Surrounding the Torre Bianca is the palace of the Bishop of Como (mentioned in the 12th century), which may contain masonry from an earlier 10th or 11th century structure. The nearby South Wing, which marks the southern boundary of the castle, was built in two stages during the 13th and 15th centuries on the foundations of an earlier building. To the west of the South Wing is a building that was built as an arsenal during the 19th century, and was fully renovated in the 20th century.
Archeological research has revealed that there were two chapels located in this bailey, though only the foundations have been discovered. In the western bailey the ruins of a church, possibly dedicated to the Madonna, can still be seen along the wall. The rest of the buildings that once occupied this bailey have all been destroyed. In the north bailey there were certainly buildings, though they have been destroyed. The sheer cliff face was not fortified with a wall until the 14th or 15th century.
The Castles of Bellinzona are a group of fortifications located around the town of Bellinzona, the capital of the Swiss canton of Ticino. Situated on the Alpine foothills, the group is composed of fortified walls and three castles named Castelgrande, Montebello and Sasso Corbaro. The Castles of Bellinzona with their defensive walls have been an UNESCO World Heritage Site since 2000.
German crusaders known as the Livonian Brothers of the Sword began construction of the Cēsis castle (Wenden) near the hill fort in 1209. When the castle was enlarged and fortified, it served as the residence for the Order's Master from 1237 till 1561, with periodic interruptions. Its ruins are some of the most majestic castle ruins in the Baltic states. Once the most important castle of the Livonian Order, it was the official residence for the masters of the order.
In 1577, during the Livonian War, the garrison destroyed the castle to prevent it from falling into the control of Ivan the Terrible, who was decisively defeated in the Battle of Wenden (1578).
In 1598 it was incorporated into the Polish-Lithuanian Commonwealth and Wenden Voivodship was created here. In 1620 Wenden was conquered by Sweden. It was rebuilt afterwards, but was destroyed again in 1703 during the Great Northern War by the Russian army and left in a ruined state. Already from the end of the 16th century, the premises of the Order's castle were adjusted to the requirements of the Cēsis Castle estate. When in 1777 the Cēsis Castle estate was obtained by Count Carl Sievers, he had his new residence house built on the site of the eastern block of the castle, joining its end wall with the fortification tower.
Since 1949, the Cēsis History Museum has been located in this New Castle of the Cēsis Castle estate. The front yard of the New Castle is enclosed by a granary and a stable-coach house, which now houses the Exhibition Hall of the Museum. Beside the granary there is the oldest brewery in Latvia, Cēsu alus darītava, which was built in 1878 during the later Count Sievers' time, but its origins date back to the period of the Livonian Order. Further on, the Cēsis Castle park is situated, which was laid out in 1812. The park has the romantic characteristic of that time, with its winding footpaths, exotic plants, and the waters of the pond reflecting the castle's ruins. Nowadays also one of the towers is open for tourists.